{"paper_id":"4cdf5804-cdfb-45bb-80b2-7606710a3fa3","body_text":"Clinical Characteristic Comparison of Neonatal Paroxysmal Supraventricular Tachycardia and Atrial Flutter | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Clinical Characteristic Comparison of Neonatal Paroxysmal Supraventricular Tachycardia and Atrial Flutter Jinchun Li, Yong Liu, Xingyu Liu, Shasha Zhang, Mi Mu This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6381125/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 8 You are reading this latest preprint version Abstract Paroxysmal atrioventricular re-entry supraventricular tachycardia (SVT) and atrial flutter (AFL) represent the two most common neonatal tachyarrhythmias. While treatment options have advanced, clinical experience with these conditions remains limited in neonatal populations. This retrospective observational study compared the clinical characteristics, management approaches, and outcomes of SVT and AFL in neonates to optimize clinical decision-making. We analyzed medical records of 43 neonates (23 SVT, 20 AFL) diagnosed over a 7-year period, including prenatal findings, clinical presentation, diagnostic workup, therapeutic interventions, and follow-up data. Our results demonstrate that SVT was characterized by significantly higher ventricular rates (p < 0.01), greater incidence of heart failure (34.8% vs 15.0%, p = 0.04), and more frequent recurrences (39.1% vs 5.0%, p = 0.01) compared to AFL. AFL cases were more frequently detected during fetal monitoring (45.0% vs 13.0%, p = 0.02) and presented earlier postnatally (median 1 vs 3 days, p = 0.03). Both arrhythmias responded effectively to pharmacotherapy, with propafenone demonstrating a dose-dependent reduction in SVT recurrence (p = 0.04). Among 34 patients with follow-up data (17 SVT, 17 AFL), all AFL cases and 70.6% of SVT cases (12/17) maintained sinus rhythm without long-term prophylaxis. These findings suggest distinct clinical profiles between neonatal SVT and AFL. While AFL rarely recurs post-conversion, SVT management should incorporate individualized risk assessment for recurrence when considering long-term prophylaxis. Health sciences/Cardiology Health sciences/Medical research Health sciences/Signs and symptoms Neonates supraventricular tachycardia atrial flutter arrhythmia treatment prophylaxis 1. Introduction Supra-ventricular tachycardia (SVT) and atrial flutter (AFL), are the two most common neonatal cardiac arrhythmias 1 , 2 . These conditions can significantly impact neonatal health if left untreated, leading to heart failure, hemodynamic instability, and, in severe cases, even death 3 . Early identification and effective management are crucial to prevent long-term complications and improve clinical outcomes. SVT is characterized by an abnormally rapid heart rate caused by re-entrant electrical circuits involving the atrioventricular node and accessory pathways. AFL, in contrast, results from rapid atrial contractions due to a single macro-reentrant circuit within the atria. While both conditions present with tachycardia, their underlying mechanisms, clinical presentations, and responses to treatment differ, necessitating distinct management strategies. The reported incidence rates of SVT and AFL in neonates are 16.3 and 2.1 per 10,000 live births, respectively 1 . Despite their relative rarity, these conditions pose diagnostic and therapeutic challenges, particularly in neonates with limited clinical presentation and non-specific symptoms. Additionally, neonatal medical staff often have limited experience managing these arrhythmias due to their infrequent occurrence, further complicating timely diagnosis and treatment. Previous studies have primarily focused on individual case series of SVT and AFL, highlighting treatment approaches and prognostic outcomes 4 , 5 . However, comprehensive comparative studies analyzing the clinical characteristics, treatment responses, and recurrence patterns of these arrhythmias remain limited 6 , 7 . Understanding these distinctions is helpful for improving diagnostic accuracy, optimizing treatment strategies, and minimizing the risk of recurrence. Furthermore, while anti-arrhythmic therapies are commonly used to manage neonatal tachyarrhythmias, their efficacy, safety, and long-term necessity remain topics of ongoing debate. The role of prophylactic medication in preventing recurrence, particularly for SVT, has not been clearly established. Some studies suggest that neonatal SVT may resolve spontaneously as the child grows, raising questions about the need for extended pharmacological intervention. This study aims to compare the clinical characteristics of neonatal SVT and AFL, assess treatment efficacy, and evaluate the necessity of long-term prophylaxis. we seek to enhance clinical understanding and improve neonatal arrhythmia management. 2. Materials and Methods 2.1 Study Population and Design This retrospective study reviewed the medical records of neonates diagnosed with SVT or AFL at the Maternal and Child Health Hospital of Hubei Province between May 2013 and January 2020. Patients were identified through the hospital's electronic medical record system, and all cases were confirmed by electrocardiographic (ECG) evaluation. Inclusion criteria consisted of neonates with sustained tachycardia diagnosed as SVT or AFL based on ECG findings. Exclusion criteria included neonates diagnosed with other forms of cardiac arrhythmias, congenital structural heart disease, or genetic syndromes affecting cardiac function. Heart failure was defined by the presence of edema, body cavity effusion, cardiac enlargement, or hepatosplenomegaly. Successful control was defined as conversion to sinus rhythm without recurrence until discharge. At follow-up, patients were deemed arrhythmia-free if off medication, asymptomatic, and without ECG-documented recurrence. Recurrence was defined as one or more sustained episodes of SVT or AFL. Demographic and clinical data collected included gestational age, birth weight, sex, mode of delivery, and perinatal history, heart rate, clinical symptoms, ECG characteristics, pharmacological interventions, and response to treatment. The study also gathered follow-up data from outpatient visits or telephone interviews, with information on recurrence rates, ongoing medication use. Parental consent was obtained before data collection, and all procedures adhered to the principles of the Declaration of Helsinki. Ethical approval was granted by the Ethics Committee of The Maternal and Child Health Hospital of Hubei Province. 2.2 Anti-arrhythmic Therapy Intravenous adenosine-5'-triphosphate (ATP) was administered at 3–5 mg per injection, repeated every 3–5 minutes as needed. Propafenone was given intravenously (1 mg/kg loading dose) with a maintenance dose of 3.5–7 µg/kg/min (maximum 12 µg/kg/min), and orally (3–7 mg/kg every 6–8 hours). Cedilanid, digoxin, and amiodarone were used per standard protocols. Doses were adjusted based on patient response and ECG findings. 2.3 Statistical Analysis Normally distributed continuous data were expressed as mean ± standard deviation (SD) and compared using independent t-tests. Skewed data were reported as median (Q1, Q3) and analyzed with Mann-Whitney U tests. Categorical data were presented as percentages and compared using χ² or Fisher’s exact tests. A P-value < 0.05 indicated statistical significance. 3. Results 3.1 Clinical Comparison of SVT and AFL Among 43 neonates, 23 had SVT and 20 had AFL. 40 were delivered via cesarean section. One term SVT infant had a minor cerebral white matter infarction, and a 29-week preterm AFL infant had a grade IV intraventricular hemorrhage. Key differences between SVT and AFL groups are summarized in Table 1 . Table 1 Comparison of clinical characteristics between SVT and AFL groups. SVT group (n = 23) AFL group (n = 20) P value Gestational age (weeks) 38.2 (37.4–40.0) 37.5 (36.4–38.5) 0.128 Birth weight (kg) 3.32 ± 0.68 3.34 ± 0.82 0.953 Preterm, n ( %) 5(21.7) 6(30.0) 0.536 Male, n ( %) 15(65.2) 11(55.0) 0.545 Intrauterine tachycardia, n ( %) 5(21.7) 12(60.0) 0.010 Onset in first 72 hours, n ( %) 14(60.9) 19(95.0) 0.011 Ventricular rate (bpm) 248.2 ± 28.6 203.7 ± 13.5 < 0.001 Heart failure, n ( %) 9(39.1) 2(10.0) 0.029 Number of episodes 3.0(1.00–7.00) 1.0 (1.0–1.0) < 0.001 Duration (days) 4.0 (1.00–14.00) 1.0 (1.0-1.9) 0.002 Medication types used 3.0 (2.00–4.00) 2.0 (1.0-2.8) 0.049 Length of hospital stay (days) 10.0 (5.00–20.00) 8.0 (7.0-13.3) 0.574 The oral propafenone oral dose (9–21 mg/kg/day) exceeded the i.v. maintenance equivalent (6-11mg/kg/day), Higher doses of oral propafenone improved SVT control. while pharmacological cardioversion was effective in all AFL cases except one, which required electrical conversion. Medication efficacy is detailed in Table 2 . Table 2 Efficacy of anti-arrhythmic medications in SVT and AFL groups. SVT group (n/N*) AFT group (n/N*) Medications and usage Conversion Prophylaxis Conversion ATP i.v. bolus 63/70 - - Cedilanid i.v. 11/25 - 5/14 Digoxin oral - 3/10 2/5 Propafenone i.v. bolus 12/29 - 6/9 Propafenone i.v. maintenance - 2/7 1/1 Propafenone oral - 10/10 3/4 Amiodarone i.v. - - 1/3 Cedilanid + Propafenone - - 1/3 * n is the effective number; N is the number of anti-arrhythmic administrations. Dashes(-) indicate no data available for that treatment modality. 3.2 Long-Term Management Follow-up data were available for 17/23 SVT patients (median age: 25.5 months [10.25, 39.75]) and 17/20 AFL patients (median age: 14 months [5.5, 32]). Among 13 SVT patients without prophylaxis, 12 remained recurrence-free; one had SVT one month post-discharge, managed with propafenone (5 months) and sotalol (4 months) without further episodes. A 2-year-old had transient SVT at 12 months, untreated. Of four SVT patients discharged with prophylaxis, one on propafenone recurred after 1 week, treated with metoprolol and amiodarone for 6 months, with no subsequent recurrence. Unmedicated and medicated SVT cases are compared in Table 3 . No AFL patients experienced recurrence; three received propafenone post-discharge (3–4weeks). Table 3 Clinical comparison between unmedicated and medicated SVT cases. Unmedicated (n = 12) Medicated (n = 5) P value SVT duration (days), mean ± SD 4.6 ± 6.0 15.2 ± 6.6 0.018 Episodes of SVT, mean ± SD 4.3 ± 4.6 8.4 ± 4.2 0.112 Medications applied, mean ± SD 2.3 ± 1.1 3.2 ± 0.8 0.115 Preexcitation, n ( %) 4(33.3) 3(60.0) 0.593 4. Discussion 4.1. Clinical Comparison and Management of SVT and AFL Both SVT and AFL are characterized by tachycardia, but their clinical presentations and responses to treatment differ significantly due to their distinct underlying pathophysiology. Both conditions can be challenging to diagnose, particularly when surface ECG findings are not definitive. In such cases, transoesophageal electrogram may be necessary for a clear diagnosis 8 . Our study found that the ventricular rate of SVT was significantly higher than that of AFL (248.2 ± 28.59 beats/min vs. 203.7 ± 13.54 beats/min), which may explain the higher incidence of heart failure in the SVT group (39.13%) compared to the AFL group (10.00%). This is consistent with previous reports, where neonatal SVT had higher ventricular rates and heart failure incidence compared to AFL 4 , 5 . Additionally, our findings show that intrauterine tachycardia was more frequently associated with AFL (60.00%) than SVT (21.70%), with AFL typically occurring earlier than SVT after delivery. Moodley et al. 9 also reported similar result. These characteristics help clinicians make timely diagnoses and treatment decisions, especially in emergent situations. SVT patients experienced more frequent episodes and required more antiarrhythmic medications than those with AFL. The median number of SVT episodes was 3, with a median time of 4 days to establish sustained sinus rhythm. In contrast, AFL typically converted to sinus rhythm within 2 days and rarely recurred post-conversion. The higher recurrence rate of SVT aligns with findings from previous studies that reported up to 33.8% recurrence among infants on digoxin or propranolol 3 . Pharmacological therapy is the cornerstone of management for both SVT and AFL. Although adenosine was not available at our hospital, ATP, which converts to adenosine, was used effectively to terminate 90% of SVT episodes, its failure to terminate SVT may be attributed to improper dosing or injection technique. Propafenone and cedilanid were also used in our study, with varying degrees of efficacy. We found that a higher dose of propafenone significantly reduced the risk of recurrence, a finding supported by other studies recommending high-dose sotalol for refractory cases 10 . In contrast, AFL was also responsive to pharmacological management, but conversion was generally slower, often taking 24–48 hours. close ventricular rate monitoring was essential to prevent circulatory compromise during drug titration. When pharmacological methods failed, electrical cardioversion was used, though it was not required as frequently in our cohort. Electrical cardioversion was effective in restoring sinus rhythm, as reported by Casey et al. 5 . 4.2. Management After Discharge The management of SVT and AFL post-discharge presents unique challenges. Most cases of neonatal SVT resolve spontaneously over time, with many neonates outgrowing the arrhythmia as accessory atrioventricular strands disappear or conduction pathways change with age 6 . However, recurrent episodes of SVT can occur before this resolution, leading to the question of whether long-term prophylactic medication is necessary. Traditional recommendations suggest a treatment course of 6–12 months for SVT patients 4 , 6 , Aljohani et al. 11 found that SVT infants without cardiac anomalies did not have an increased risk of recurrence with shorter treatment courses of 4–6 months. In our cohort, of the 13 SVT patients not prescribed long-term prophylaxis, 12 remained free of recurrence, suggesting that not all neonates with SVT require prolonged antiarrhythmic treatment. Our data support a more cautious approach, where prophylactic therapy is tailored based on the specific clinical characteristics and risk factors of each patient. For the SVT patients with difficulty in control, prophylactic medicine should be given. In contrast, AFL rarely recurs post-conversion, as shown in our study and supported by other studies, which report no recurrence after successful conversion 5 . Our cohort also showed that prophylactic medication for AFL was generally unnecessary, with only 3 patients receiving short-term medication. This finding is consistent with the recommendation to avoid long-term prophylaxis for neonates with AFL unless there are underlying cardiac conditions 12 . 5. Conclusion Neonatal SVT and AFL exhibit distinct clinical and management characteristics. While SVT may require individualized long-term prophylaxis, AFL recurrence after successful conversion is uncommon. Declarations Data Availability Statement All data generated or analyzed during this study are included in this article. Further enquiries can be directed to the corresponding author. Acknowledgments We would like to thank all the infants and their parents of this study and the clinical staff at the Department of Neonatology of Maternal and Child Health Hospital of Hubei Province. Competing interests: The authors declare no competing interests. Funding: This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. Author information Authors and Affiliations 1 Department of Neonatology, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan city, Hubei Province, People’s Republic of China Jinchun Li, Yong Liu 2 Department of Reproduction, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan city, Hubei Province, People’s Republic of China Xingyu Liu 3 Department of Pharmacy, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, People’s Republic of China Shasha Zhang 4 Department of Electrocardiography, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, People’s Republic of China Mi Mu Author Contributions Y.L. (Yong Liu) conceived and designed the study, performed statistical analysis, and supervised the research. As corresponding author, he critically revised the manuscript and ensured data accuracy. J.L. (Jinchun Li) contributed equally to study design, drafted the manuscript, managed data curation, prepared tables, and provided critical revisions. X.L. (Xingyu Liu) conducted literature reviews, assisted in data interpretation, and supported statistical analysis during revisions. S.Z. (Shasha Zhang) extracted and verified medication data for all neonatal patients, performed analysis, and played a key role in follow-up efforts. M.M. (Mi Mu) conducted statistical analysis of ECG data and contributed to manuscript proofreading. All authors reviewed and approved the final manuscript. Correspondence to Yong Liu Ethics declarations Consent for publication All authors have declared their consent for this publication. Competing interests The authors declare no competing interests. Ethical approval This study was conducted according to the principles of the Declaration of Helsinki, approved by the Ethics Committee of The Maternal and Child Health Hospital of Hubei Province(registration number 2021-IEC-LW038) and a waiver of informed content was obtained. References Turner, C. J. & Wren, C. The epidemiology of arrhythmia in infants: A population-based study. J. Paediatr. Child. Health . 49 , 278–281. https://doi.org/10.1111/jpc.12155 (2013). Brugada, J. et al. Pharmacological and non-pharmacological therapy for arrhythmias in the pediatric population: EHRA and AEPC-arrhythmia working group joint consensus statement. Europace 15 , 1337–1382. https://doi.org/10.1093/europace/eut082 (2013). Sanatani, S. et al.. The study of antiarrhythmic medications in infancy (SAMIS): A multicenter, randomized controlled trial comparing the efficacy and safety of digoxin versus propranolol for prophylaxis of supraventricular tachycardia in infants. Circ. Arrhythm. Electrophysiol. 5 , 984–991. https://doi.org/10.1161/CIRCEP.112.972620 (2012). Gilljam, T., Jaeggi, E. & Gow, R. M. Neonatal supraventricular tachycardia: Outcomes over a 27-year period at a single institution. Acta Paediatr. 97 , 1035–1039. https://doi.org/10.1111/j.1651-2227.2008.00823.x (2008). Casey, F. A., McCrindle, B. W., Hamilton, R. M. & Gow, R. M. Neonatal atrial flutter: Significant early morbidity and excellent long-term prognosis. Am. Heart J. 133 , 302–306. https://doi.org/10.1016/S0002-8703(97)70224-2 (1997). Weindling, S. N., Saul, J. P. & Walsh, E. P. Efficacy and risks of medical therapy for supraventricular tachycardia in neonates and infants. Am. Heart J. 131 , 66–72. https://doi.org/10.1016/S0002-8703(96)90052-6 (1996). Miyoshi, T. et al. Antenatal therapy for fetal supraventricular tachyarrhythmias: Multicenter trial. J. Am. Coll. Cardiol. 74 , 874–885. https://doi.org/10.1016/j.jacc.2019.06.024 (2019). Dunnigan, A., Benson, W. Jr. & Benditt, D. G. Atrial flutter in infancy: Diagnosis, clinical features, and treatment. Pediatrics 75 , 725–729. https://doi.org/10.1542/peds.75.4.725 (1985). Moodley, S., Sanatani, S., Potts, J. E. & Sandor, G. G. Postnatal outcome in patients with fetal tachycardia. Pediatr. Cardiol. 34 , 81–87. https://doi.org/10.1007/s00246-012-0392-7 (2013). Knudson, J. D. et al. High-dose sotalol is safe and effective in neonates and infants with refractory supraventricular tachyarrhythmias. Pediatr. Cardiol. 32 , 896–903. https://doi.org/10.1007/s00246-011-0010-0 (2011). Aljohani, O. A. et al. Antiarrhythmic treatment duration and tachycardia recurrence in infants with supraventricular tachycardia. Pediatr. Cardiol. 42 , 716–720. https://doi.org/10.1007/s00246-020-02534-5 (2021). Lisowski, L. A. et al. Atrial flutter in the perinatal age group: Diagnosis, management and outcome. J. Am. Coll. Cardiol. 35 , 771–777. https://doi.org/10.1016/S0735-1097(99)00589-6 (2000). Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviews received at journal 16 Aug, 2025 Reviewers agreed at journal 10 Aug, 2025 Reviewers agreed at journal 05 Aug, 2025 Reviewers invited by journal 29 Jul, 2025 Editor assigned by journal 24 Jul, 2025 Editor invited by journal 22 Apr, 2025 Submission checks completed at journal 22 Apr, 2025 First submitted to journal 05 Apr, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {\"props\":{\"pageProps\":{\"initialData\":{\"identity\":\"rs-6381125\",\"acceptedTermsAndConditions\":true,\"allowDirectSubmit\":false,\"archivedVersions\":[],\"articleType\":\"Article\",\"associatedPublications\":[],\"authors\":[{\"id\":449043400,\"identity\":\"98ec2c53-4dc6-4616-a189-34467c45ddfd\",\"order_by\":0,\"name\":\"Jinchun Li\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Huazhong University of Science and Technology\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Jinchun\",\"middleName\":\"\",\"lastName\":\"Li\",\"suffix\":\"\"},{\"id\":449043401,\"identity\":\"8e2c082b-d43e-4a95-b5ea-1a1df2c86e16\",\"order_by\":1,\"name\":\"Yong Liu\",\"email\":\"data:image/png;base64,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\",\"orcid\":\"\",\"institution\":\"Huazhong University of Science and Technology\",\"correspondingAuthor\":true,\"prefix\":\"\",\"firstName\":\"Yong\",\"middleName\":\"\",\"lastName\":\"Liu\",\"suffix\":\"\"},{\"id\":449043402,\"identity\":\"872e5f8f-454c-4144-8734-0d8f2fecccb7\",\"order_by\":2,\"name\":\"Xingyu Liu\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Huazhong University of Science and Technology\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Xingyu\",\"middleName\":\"\",\"lastName\":\"Liu\",\"suffix\":\"\"},{\"id\":449043403,\"identity\":\"d8621af4-6ea2-4659-88e5-12ea743e1217\",\"order_by\":3,\"name\":\"Shasha Zhang\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Huazhong University of Science and Technology\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Shasha\",\"middleName\":\"\",\"lastName\":\"Zhang\",\"suffix\":\"\"},{\"id\":449043404,\"identity\":\"e1dc4789-a9d6-44e9-a144-6edefe34b99d\",\"order_by\":4,\"name\":\"Mi Mu\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Huazhong University of Science and Technology\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Mi\",\"middleName\":\"\",\"lastName\":\"Mu\",\"suffix\":\"\"}],\"badges\":[],\"createdAt\":\"2025-04-05 09:23:18\",\"currentVersionCode\":1,\"declarations\":\"\",\"doi\":\"10.21203/rs.3.rs-6381125/v1\",\"doiUrl\":\"https://doi.org/10.21203/rs.3.rs-6381125/v1\",\"draftVersion\":[],\"editorialEvents\":[],\"editorialNote\":\"\",\"failedWorkflow\":false,\"files\":[{\"id\":81675178,\"identity\":\"3b129b77-a875-4b1b-b205-80900e339c3c\",\"added_by\":\"auto\",\"created_at\":\"2025-04-30 07:13:57\",\"extension\":\"pdf\",\"order_by\":0,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"manuscript-pdf\",\"size\":621495,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"manuscript.pdf\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-6381125/v1/7429b091-c925-401a-ad7c-21b727f73c20.pdf\"}],\"financialInterests\":\"No competing interests reported.\",\"formattedTitle\":\"Clinical Characteristic Comparison of Neonatal Paroxysmal Supraventricular Tachycardia and Atrial Flutter\",\"fulltext\":[{\"header\":\"1. Introduction\",\"content\":\"\\u003cp\\u003eSupra-ventricular tachycardia (SVT) and atrial flutter (AFL), are the two most common neonatal cardiac arrhythmias \\u003csup\\u003e\\u003cspan citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e1\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR2\\\" class=\\\"CitationRef\\\"\\u003e2\\u003c/span\\u003e\\u003c/sup\\u003e. These conditions can significantly impact neonatal health if left untreated, leading to heart failure, hemodynamic instability, and, in severe cases, even death \\u003csup\\u003e\\u003cspan citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e3\\u003c/span\\u003e\\u003c/sup\\u003e. Early identification and effective management are crucial to prevent long-term complications and improve clinical outcomes. SVT is characterized by an abnormally rapid heart rate caused by re-entrant electrical circuits involving the atrioventricular node and accessory pathways. AFL, in contrast, results from rapid atrial contractions due to a single macro-reentrant circuit within the atria. While both conditions present with tachycardia, their underlying mechanisms, clinical presentations, and responses to treatment differ, necessitating distinct management strategies. The reported incidence rates of SVT and AFL in neonates are 16.3 and 2.1 per 10,000 live births, respectively \\u003csup\\u003e\\u003cspan citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e1\\u003c/span\\u003e\\u003c/sup\\u003e. Despite their relative rarity, these conditions pose diagnostic and therapeutic challenges, particularly in neonates with limited clinical presentation and non-specific symptoms. Additionally, neonatal medical staff often have limited experience managing these arrhythmias due to their infrequent occurrence, further complicating timely diagnosis and treatment.\\u003c/p\\u003e \\u003cp\\u003ePrevious studies have primarily focused on individual case series of SVT and AFL, highlighting treatment approaches and prognostic outcomes \\u003csup\\u003e\\u003cspan citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e4\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e\\u003c/sup\\u003e. However, comprehensive comparative studies analyzing the clinical characteristics, treatment responses, and recurrence patterns of these arrhythmias remain limited \\u003csup\\u003e\\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e6\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR7\\\" class=\\\"CitationRef\\\"\\u003e7\\u003c/span\\u003e\\u003c/sup\\u003e. Understanding these distinctions is helpful for improving diagnostic accuracy, optimizing treatment strategies, and minimizing the risk of recurrence. Furthermore, while anti-arrhythmic therapies are commonly used to manage neonatal tachyarrhythmias, their efficacy, safety, and long-term necessity remain topics of ongoing debate. The role of prophylactic medication in preventing recurrence, particularly for SVT, has not been clearly established. Some studies suggest that neonatal SVT may resolve spontaneously as the child grows, raising questions about the need for extended pharmacological intervention.\\u003c/p\\u003e \\u003cp\\u003eThis study aims to compare the clinical characteristics of neonatal SVT and AFL, assess treatment efficacy, and evaluate the necessity of long-term prophylaxis. we seek to enhance clinical understanding and improve neonatal arrhythmia management.\\u003c/p\\u003e\"},{\"header\":\"2. Materials and Methods\",\"content\":\"\\u003cdiv id=\\\"Sec3\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e2.1 Study Population and Design\\u003c/h2\\u003e \\u003cp\\u003eThis retrospective study reviewed the medical records of neonates diagnosed with SVT or AFL at the Maternal and Child Health Hospital of Hubei Province between May 2013 and January 2020. Patients were identified through the hospital's electronic medical record system, and all cases were confirmed by electrocardiographic (ECG) evaluation. Inclusion criteria consisted of neonates with sustained tachycardia diagnosed as SVT or AFL based on ECG findings. Exclusion criteria included neonates diagnosed with other forms of cardiac arrhythmias, congenital structural heart disease, or genetic syndromes affecting cardiac function. Heart failure was defined by the presence of edema, body cavity effusion, cardiac enlargement, or hepatosplenomegaly. Successful control was defined as conversion to sinus rhythm without recurrence until discharge. At follow-up, patients were deemed arrhythmia-free if off medication, asymptomatic, and without ECG-documented recurrence. Recurrence was defined as one or more sustained episodes of SVT or AFL.\\u003c/p\\u003e \\u003cp\\u003eDemographic and clinical data collected included gestational age, birth weight, sex, mode of delivery, and perinatal history, heart rate, clinical symptoms, ECG characteristics, pharmacological interventions, and response to treatment. The study also gathered follow-up data from outpatient visits or telephone interviews, with information on recurrence rates, ongoing medication use. Parental consent was obtained before data collection, and all procedures adhered to the principles of the Declaration of Helsinki. Ethical approval was granted by the Ethics Committee of The Maternal and Child Health Hospital of Hubei Province.\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec4\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e2.2 Anti-arrhythmic Therapy\\u003c/h2\\u003e \\u003cp\\u003eIntravenous adenosine-5'-triphosphate (ATP) was administered at 3\\u0026ndash;5 mg per injection, repeated every 3\\u0026ndash;5 minutes as needed. Propafenone was given intravenously (1 mg/kg loading dose) with a maintenance dose of 3.5\\u0026ndash;7 \\u0026micro;g/kg/min (maximum 12 \\u0026micro;g/kg/min), and orally (3\\u0026ndash;7 mg/kg every 6\\u0026ndash;8 hours). Cedilanid, digoxin, and amiodarone were used per standard protocols. Doses were adjusted based on patient response and ECG findings.\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec5\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e2.3 Statistical Analysis\\u003c/h2\\u003e \\u003cp\\u003eNormally distributed continuous data were expressed as mean\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;standard deviation (SD) and compared using independent t-tests. Skewed data were reported as median (Q1, Q3) and analyzed with Mann-Whitney U tests. Categorical data were presented as percentages and compared using χ\\u0026sup2; or Fisher\\u0026rsquo;s exact tests. A P-value\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.05 indicated statistical significance.\\u003c/p\\u003e \\u003c/div\\u003e\"},{\"header\":\"3. Results\",\"content\":\"\\u003cdiv id=\\\"Sec7\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e3.1 Clinical Comparison of SVT and AFL\\u003c/h2\\u003e \\u003cp\\u003eAmong 43 neonates, 23 had SVT and 20 had AFL. 40 were delivered via cesarean section. One term SVT infant had a minor cerebral white matter infarction, and a 29-week preterm AFL infant had a grade IV intraventricular hemorrhage. Key differences between SVT and AFL groups are summarized in Table\\u0026nbsp;\\u003cspan refid=\\\"Tab1\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e.\\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab1\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 1\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eComparison of clinical characteristics between SVT and AFL groups.\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"4\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c4\\\" colnum=\\\"4\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u0026nbsp;\\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eSVT group\\u003c/p\\u003e \\u003cp\\u003e(n\\u0026thinsp;=\\u0026thinsp;23)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003eAFL group\\u003c/p\\u003e \\u003cp\\u003e(n\\u0026thinsp;=\\u0026thinsp;20)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u003cem\\u003eP\\u003c/em\\u003e value\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eGestational age (weeks)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e38.2 (37.4\\u0026ndash;40.0)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e37.5 (36.4\\u0026ndash;38.5)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.128\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eBirth weight (kg)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e3.32\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.68\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e3.34\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.82\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.953\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003ePreterm, n ( %)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e5(21.7)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e6(30.0)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.536\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eMale, n ( %)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e15(65.2)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e11(55.0)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.545\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eIntrauterine tachycardia, n ( %)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e5(21.7)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e12(60.0)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u003cb\\u003e0.010\\u003c/b\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eOnset in first 72 hours, n ( %)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e14(60.9)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e19(95.0)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u003cb\\u003e0.011\\u003c/b\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eVentricular rate (bpm)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e248.2\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;28.6\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e203.7\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;13.5\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u003cb\\u003e\\u0026lt;\\u0026thinsp;0.001\\u003c/b\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eHeart failure, n ( %)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e9(39.1)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e2(10.0)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u003cb\\u003e0.029\\u003c/b\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eNumber of episodes\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e3.0(1.00\\u0026ndash;7.00)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e1.0 (1.0\\u0026ndash;1.0)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u003cb\\u003e\\u0026lt;\\u0026thinsp;0.001\\u003c/b\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eDuration (days)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e4.0 (1.00\\u0026ndash;14.00)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e1.0 (1.0-1.9)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u003cb\\u003e0.002\\u003c/b\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eMedication types used\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e3.0 (2.00\\u0026ndash;4.00)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e2.0 (1.0-2.8)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u003cb\\u003e0.049\\u003c/b\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eLength of hospital stay (days)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e10.0 (5.00\\u0026ndash;20.00)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e8.0 (7.0-13.3)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.574\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e \\u003cp\\u003eThe oral propafenone oral dose (9\\u0026ndash;21 mg/kg/day) exceeded the i.v. maintenance equivalent (6-11mg/kg/day), Higher doses of oral propafenone improved SVT control. while pharmacological cardioversion was effective in all AFL cases except one, which required electrical conversion. Medication efficacy is detailed in Table\\u0026nbsp;\\u003cspan refid=\\\"Tab2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e.\\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab2\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 2\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eEfficacy of anti-arrhythmic medications in SVT and AFL groups.\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"4\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c4\\\" colnum=\\\"4\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u0026nbsp;\\u003c/th\\u003e \\u003cth align=\\\"left\\\" colspan=\\\"2\\\" nameend=\\\"c3\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003eSVT group\\u003c/p\\u003e \\u003cp\\u003e(n/N*)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003eAFT group (n/N*)\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eMedications and usage\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eConversion\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003eProphylaxis\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003eConversion\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eATP i.v. bolus\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e63/70\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eCedilanid i.v.\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e11/25\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e5/14\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eDigoxin oral\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e3/10\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e2/5\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003ePropafenone i.v. bolus\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e12/29\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e6/9\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003ePropafenone i.v. maintenance\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e2/7\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e1/1\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003ePropafenone oral\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e10/10\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e3/4\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eAmiodarone i.v.\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e1/3\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eCedilanid\\u0026thinsp;+\\u0026thinsp;Propafenone\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e-\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e1/3\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003ctfoot\\u003e \\u003ctr\\u003e\\u003ctd colspan=\\\"4\\\"\\u003e* n is the effective number; N is the number of anti-arrhythmic administrations.\\u003c/td\\u003e\\u003c/tr\\u003e \\u003ctr\\u003e\\u003ctd colspan=\\\"4\\\"\\u003eDashes(-) indicate no data available for that treatment modality.\\u003c/td\\u003e\\u003c/tr\\u003e \\u003c/tfoot\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec8\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e3.2 Long-Term Management\\u003c/h2\\u003e \\u003cp\\u003eFollow-up data were available for 17/23 SVT patients (median age: 25.5 months [10.25, 39.75]) and 17/20 AFL patients (median age: 14 months [5.5, 32]). Among 13 SVT patients without prophylaxis, 12 remained recurrence-free; one had SVT one month post-discharge, managed with propafenone (5 months) and sotalol (4 months) without further episodes. A 2-year-old had transient SVT at 12 months, untreated. Of four SVT patients discharged with prophylaxis, one on propafenone recurred after 1 week, treated with metoprolol and amiodarone for 6 months, with no subsequent recurrence. Unmedicated and medicated SVT cases are compared in Table\\u0026nbsp;\\u003cspan refid=\\\"Tab3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e. No AFL patients experienced recurrence; three received propafenone post-discharge (3\\u0026ndash;4weeks).\\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab3\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 3\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eClinical comparison between unmedicated and medicated SVT cases.\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"4\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c4\\\" colnum=\\\"4\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u0026nbsp;\\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eUnmedicated\\u003c/p\\u003e \\u003cp\\u003e(n\\u0026thinsp;=\\u0026thinsp;12)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003eMedicated\\u003c/p\\u003e \\u003cp\\u003e(n\\u0026thinsp;=\\u0026thinsp;5)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u003cem\\u003eP\\u003c/em\\u003e value\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eSVT duration (days), mean\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;SD\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e4.6\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;6.0\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e15.2\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;6.6\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e\\u003cb\\u003e0.018\\u003c/b\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eEpisodes of SVT, mean\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;SD\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e4.3\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;4.6\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e8.4\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;4.2\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.112\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eMedications applied, mean\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;SD\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e2.3\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;1.1\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e3.2\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.8\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.115\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003ePreexcitation, \\u003cem\\u003en\\u003c/em\\u003e( %)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e4(33.3)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e3(60.0)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e0.593\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e \\u003c/div\\u003e\"},{\"header\":\"4. Discussion\",\"content\":\"\\u003cdiv id=\\\"Sec10\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e4.1. Clinical Comparison and Management of SVT and AFL\\u003c/h2\\u003e \\u003cp\\u003eBoth SVT and AFL are characterized by tachycardia, but their clinical presentations and responses to treatment differ significantly due to their distinct underlying pathophysiology. Both conditions can be challenging to diagnose, particularly when surface ECG findings are not definitive. In such cases, transoesophageal electrogram may be necessary for a clear diagnosis \\u003csup\\u003e\\u003cspan citationid=\\\"CR8\\\" class=\\\"CitationRef\\\"\\u003e8\\u003c/span\\u003e\\u003c/sup\\u003e.\\u003c/p\\u003e \\u003cp\\u003eOur study found that the ventricular rate of SVT was significantly higher than that of AFL (248.2\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;28.59 beats/min vs. 203.7\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;13.54 beats/min), which may explain the higher incidence of heart failure in the SVT group (39.13%) compared to the AFL group (10.00%). This is consistent with previous reports, where neonatal SVT had higher ventricular rates and heart failure incidence compared to AFL \\u003csup\\u003e\\u003cspan citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e4\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e\\u003c/sup\\u003e. Additionally, our findings show that intrauterine tachycardia was more frequently associated with AFL (60.00%) than SVT (21.70%), with AFL typically occurring earlier than SVT after delivery. Moodley et al. \\u003csup\\u003e\\u003cspan citationid=\\\"CR9\\\" class=\\\"CitationRef\\\"\\u003e9\\u003c/span\\u003e\\u003c/sup\\u003e also reported similar result. These characteristics help clinicians make timely diagnoses and treatment decisions, especially in emergent situations.\\u003c/p\\u003e \\u003cp\\u003eSVT patients experienced more frequent episodes and required more antiarrhythmic medications than those with AFL. The median number of SVT episodes was 3, with a median time of 4 days to establish sustained sinus rhythm. In contrast, AFL typically converted to sinus rhythm within 2 days and rarely recurred post-conversion. The higher recurrence rate of SVT aligns with findings from previous studies that reported up to 33.8% recurrence among infants on digoxin or propranolol \\u003csup\\u003e\\u003cspan citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e3\\u003c/span\\u003e\\u003c/sup\\u003e.\\u003c/p\\u003e \\u003cp\\u003ePharmacological therapy is the cornerstone of management for both SVT and AFL. Although adenosine was not available at our hospital, ATP, which converts to adenosine, was used effectively to terminate 90% of SVT episodes, its failure to terminate SVT may be attributed to improper dosing or injection technique. Propafenone and cedilanid were also used in our study, with varying degrees of efficacy. We found that a higher dose of propafenone significantly reduced the risk of recurrence, a finding supported by other studies recommending high-dose sotalol for refractory cases \\u003csup\\u003e\\u003cspan citationid=\\\"CR10\\\" class=\\\"CitationRef\\\"\\u003e10\\u003c/span\\u003e\\u003c/sup\\u003e.\\u003c/p\\u003e \\u003cp\\u003eIn contrast, AFL was also responsive to pharmacological management, but conversion was generally slower, often taking 24\\u0026ndash;48 hours. close ventricular rate monitoring was essential to prevent circulatory compromise during drug titration. When pharmacological methods failed, electrical cardioversion was used, though it was not required as frequently in our cohort. Electrical cardioversion was effective in restoring sinus rhythm, as reported by Casey et al. \\u003csup\\u003e\\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e\\u003c/sup\\u003e.\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec11\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e4.2. Management After Discharge\\u003c/h2\\u003e \\u003cp\\u003eThe management of SVT and AFL post-discharge presents unique challenges. Most cases of neonatal SVT resolve spontaneously over time, with many neonates outgrowing the arrhythmia as accessory atrioventricular strands disappear or conduction pathways change with age \\u003csup\\u003e\\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e6\\u003c/span\\u003e\\u003c/sup\\u003e. However, recurrent episodes of SVT can occur before this resolution, leading to the question of whether long-term prophylactic medication is necessary. Traditional recommendations suggest a treatment course of 6\\u0026ndash;12 months for SVT patients \\u003csup\\u003e\\u003cspan citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e4\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e6\\u003c/span\\u003e\\u003c/sup\\u003e, Aljohani et al.\\u003csup\\u003e\\u003cspan citationid=\\\"CR11\\\" class=\\\"CitationRef\\\"\\u003e11\\u003c/span\\u003e\\u003c/sup\\u003e found that SVT infants without cardiac anomalies did not have an increased risk of recurrence with shorter treatment courses of 4\\u0026ndash;6 months. In our cohort, of the 13 SVT patients not prescribed long-term prophylaxis, 12 remained free of recurrence, suggesting that not all neonates with SVT require prolonged antiarrhythmic treatment. Our data support a more cautious approach, where prophylactic therapy is tailored based on the specific clinical characteristics and risk factors of each patient. For the SVT patients with difficulty in control, prophylactic medicine should be given.\\u003c/p\\u003e \\u003cp\\u003eIn contrast, AFL rarely recurs post-conversion, as shown in our study and supported by other studies, which report no recurrence after successful conversion \\u003csup\\u003e\\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e\\u003c/sup\\u003e. Our cohort also showed that prophylactic medication for AFL was generally unnecessary, with only 3 patients receiving short-term medication. This finding is consistent with the recommendation to avoid long-term prophylaxis for neonates with AFL unless there are underlying cardiac conditions \\u003csup\\u003e\\u003cspan citationid=\\\"CR12\\\" class=\\\"CitationRef\\\"\\u003e12\\u003c/span\\u003e\\u003c/sup\\u003e.\\u003c/p\\u003e \\u003c/div\\u003e\"},{\"header\":\"5. Conclusion\",\"content\":\"\\u003cp\\u003eNeonatal SVT and AFL exhibit distinct clinical and management characteristics. While SVT may require individualized long-term prophylaxis, AFL recurrence after successful conversion is uncommon.\\u003c/p\\u003e\"},{\"header\":\"Declarations\",\"content\":\"\\u003cp\\u003e\\u003cstrong\\u003eData Availability Statement\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eAll data generated or analyzed during this study are included in this article. Further enquiries can be directed to the corresponding author.\\u003c/p\\u003e\\u003cp\\u003e\\u003cstrong\\u003eAcknowledgments\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eWe would like to thank all the infants and their parents of this study and the clinical staff at the Department of Neonatology of Maternal and Child Health Hospital of Hubei Province.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eCompeting interests:\\u0026nbsp;\\u003c/strong\\u003eThe authors declare no competing interests. \\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eFunding:\\u003c/strong\\u003e\\u0026nbsp; This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. \\u0026nbsp;\\u003c/p\\u003e\\n\\n\\u003cp\\u003e\\u003cstrong\\u003eAuthor information\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eAuthors and Affiliations\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003csup\\u003e1\\u003c/sup\\u003eDepartment of Neonatology, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan city, Hubei Province, People\\u0026rsquo;s Republic of China\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003eJinchun Li, Yong Liu\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003csup\\u003e2\\u003c/sup\\u003eDepartment of Reproduction, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan city, Hubei Province, People\\u0026rsquo;s Republic of China\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003eXingyu Liu\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003csup\\u003e3\\u003c/sup\\u003eDepartment of Pharmacy, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, People\\u0026rsquo;s Republic of China\\u003c/p\\u003e\\n\\u003cp\\u003eShasha Zhang\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003csup\\u003e4\\u003c/sup\\u003eDepartment of Electrocardiography, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, People\\u0026rsquo;s Republic of China\\u003c/p\\u003e\\n\\u003cp\\u003eMi Mu\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eAuthor Contributions\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eY.L. (Yong Liu) conceived and designed the study, performed statistical analysis, and supervised the research. As corresponding author, he critically revised the manuscript and ensured data accuracy. J.L. (Jinchun Li) contributed equally to study design, drafted the manuscript, managed data curation, prepared tables, and provided critical revisions. X.L. (Xingyu Liu) conducted literature reviews, assisted in data interpretation, and supported statistical analysis during revisions. S.Z. (Shasha Zhang) extracted and verified medication data for all neonatal patients, performed analysis, and played a key role in follow-up efforts. M.M. (Mi Mu) conducted statistical analysis of ECG data and contributed to manuscript proofreading.\\u003c/p\\u003e\\n\\u003cp\\u003eAll authors reviewed and approved the final manuscript. \\u0026nbsp;\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003eCorrespondence to Yong Liu\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eEthics declarations\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eConsent for publication\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eAll authors have declared their consent for this publication.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eCompeting interests\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThe authors declare no competing interests.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eEthical approval\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThis study was conducted according to the principles of the Declaration of Helsinki,\\u003c/p\\u003e\\n\\u003cp\\u003eapproved by the Ethics Committee of The Maternal and Child Health Hospital of Hubei Province(registration number 2021-IEC-LW038) and a waiver of informed content was obtained.\\u003c/p\\u003e\"},{\"header\":\"References\",\"content\":\"\\u003col\\u003e\\u003cli\\u003e\\u003cspan\\u003eTurner, C. J. \\u0026amp; Wren, C. The epidemiology of arrhythmia in infants: A population-based study. \\u003cem\\u003eJ. Paediatr. Child. Health\\u003c/em\\u003e. \\u003cb\\u003e49\\u003c/b\\u003e, 278\\u0026ndash;281. \\u003cspan class=\\\"ExternalRef\\\"\\u003e\\u003cspan class=\\\"RefSource\\\"\\u003ehttps://doi.org/10.1111/jpc.12155\\u003c/span\\u003e\\u003cspan address=\\\"10.1111/jpc.12155\\\" targettype=\\\"DOI\\\" class=\\\"RefTarget\\\"\\u003e\\u003c/span\\u003e\\u003c/span\\u003e (2013).\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eBrugada, J. et al. Pharmacological and non-pharmacological therapy for arrhythmias in the pediatric population: EHRA and AEPC-arrhythmia working group joint consensus statement. \\u003cem\\u003eEuropace\\u003c/em\\u003e \\u003cb\\u003e15\\u003c/b\\u003e, 1337\\u0026ndash;1382. \\u003cspan class=\\\"ExternalRef\\\"\\u003e\\u003cspan class=\\\"RefSource\\\"\\u003ehttps://doi.org/10.1093/europace/eut082\\u003c/span\\u003e\\u003cspan address=\\\"10.1093/europace/eut082\\\" targettype=\\\"DOI\\\" class=\\\"RefTarget\\\"\\u003e\\u003c/span\\u003e\\u003c/span\\u003e (2013).\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eSanatani, S. et al.. The study of antiarrhythmic medications in infancy (SAMIS): A multicenter, randomized controlled trial comparing the efficacy and safety of digoxin versus propranolol for prophylaxis of supraventricular tachycardia in infants. \\u003cem\\u003eCirc. Arrhythm. 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Cardiol.\\u003c/em\\u003e \\u003cb\\u003e35\\u003c/b\\u003e, 771\\u0026ndash;777. \\u003cspan class=\\\"ExternalRef\\\"\\u003e\\u003cspan class=\\\"RefSource\\\"\\u003ehttps://doi.org/10.1016/S0735-1097(99)00589-6\\u003c/span\\u003e\\u003cspan address=\\\"10.1016/S0735-1097(99)00589-6\\\" targettype=\\\"DOI\\\" class=\\\"RefTarget\\\"\\u003e\\u003c/span\\u003e\\u003c/span\\u003e (2000).\\u003c/span\\u003e\\u003c/li\\u003e\\u003c/ol\\u003e\"}],\"fulltextSource\":\"\",\"fullText\":\"\",\"funders\":[],\"hasAdminPriorityOnWorkflow\":false,\"hasManuscriptDocX\":true,\"hasOptedInToPreprint\":true,\"hasPassedJournalQc\":\"\",\"hasAnyPriority\":true,\"hideJournal\":false,\"highlight\":\"\",\"institution\":\"\",\"isAcceptedByJournal\":false,\"isAuthorSuppliedPdf\":false,\"isDeskRejected\":\"\",\"isHiddenFromSearch\":false,\"isInQc\":false,\"isInWorkflow\":false,\"isPdf\":false,\"isPdfUpToDate\":true,\"isWithdrawnOrRetracted\":false,\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"scientific-reports\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":false,\"externalIdentity\":\"scirep\",\"sideBox\":\"Learn more about [Scientific Reports](http://www.nature.com/srep/)\",\"snPcode\":\"\",\"submissionUrl\":\"\",\"title\":\"Scientific Reports\",\"twitterHandle\":\"\",\"acdcEnabled\":true,\"dfaEnabled\":true,\"editorialSystem\":\"stoa\",\"reportingPortfolio\":\"Scientific Reports\",\"inReviewEnabled\":true,\"inReviewRevisionsEnabled\":true},\"keywords\":\"Neonates, supraventricular tachycardia, atrial flutter, arrhythmia, treatment, prophylaxis\",\"lastPublishedDoi\":\"10.21203/rs.3.rs-6381125/v1\",\"lastPublishedDoiUrl\":\"https://doi.org/10.21203/rs.3.rs-6381125/v1\",\"license\":{\"name\":\"CC BY 4.0\",\"url\":\"https://creativecommons.org/licenses/by/4.0/\"},\"manuscriptAbstract\":\"\\u003cp\\u003eParoxysmal atrioventricular re-entry supraventricular tachycardia (SVT) and atrial flutter (AFL) represent the two most common neonatal tachyarrhythmias. While treatment options have advanced, clinical experience with these conditions remains limited in neonatal populations. This retrospective observational study compared the clinical characteristics, management approaches, and outcomes of SVT and AFL in neonates to optimize clinical decision-making. We analyzed medical records of 43 neonates (23 SVT, 20 AFL) diagnosed over a 7-year period, including prenatal findings, clinical presentation, diagnostic workup, therapeutic interventions, and follow-up data. Our results demonstrate that SVT was characterized by significantly higher ventricular rates (p\\u0026thinsp;\\u0026lt;\\u0026thinsp;0.01), greater incidence of heart failure (34.8% vs 15.0%, p\\u0026thinsp;=\\u0026thinsp;0.04), and more frequent recurrences (39.1% vs 5.0%, p\\u0026thinsp;=\\u0026thinsp;0.01) compared to AFL. AFL cases were more frequently detected during fetal monitoring (45.0% vs 13.0%, p\\u0026thinsp;=\\u0026thinsp;0.02) and presented earlier postnatally (median 1 vs 3 days, p\\u0026thinsp;=\\u0026thinsp;0.03). Both arrhythmias responded effectively to pharmacotherapy, with propafenone demonstrating a dose-dependent reduction in SVT recurrence (p\\u0026thinsp;=\\u0026thinsp;0.04). Among 34 patients with follow-up data (17 SVT, 17 AFL), all AFL cases and 70.6% of SVT cases (12/17) maintained sinus rhythm without long-term prophylaxis. These findings suggest distinct clinical profiles between neonatal SVT and AFL. While AFL rarely recurs post-conversion, SVT management should incorporate individualized risk assessment for recurrence when considering long-term prophylaxis.\\u003c/p\\u003e\",\"manuscriptTitle\":\"Clinical Characteristic Comparison of Neonatal Paroxysmal Supraventricular Tachycardia and Atrial Flutter\",\"msid\":\"\",\"msnumber\":\"\",\"nonDraftVersions\":[{\"code\":1,\"date\":\"2025-04-30 07:05:52\",\"doi\":\"10.21203/rs.3.rs-6381125/v1\",\"editorialEvents\":[{\"type\":\"communityComments\",\"content\":0},{\"type\":\"editorInvitedReview\",\"content\":\"\",\"date\":\"2025-08-16T17:57:13+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"104610786129357341006894928561318092402\",\"date\":\"2025-08-10T11:31:43+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"262689251793551877454297951211881555172\",\"date\":\"2025-08-05T12:28:52+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewersInvited\",\"content\":\"\",\"date\":\"2025-07-29T18:06:07+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"editorAssigned\",\"content\":\"\",\"date\":\"2025-07-24T08:29:53+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"editorInvited\",\"content\":\"\",\"date\":\"2025-04-22T16:36:25+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"checksComplete\",\"content\":\"\",\"date\":\"2025-04-22T07:23:33+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"submitted\",\"content\":\"Scientific Reports\",\"date\":\"2025-04-05T09:18:34+00:00\",\"index\":\"\",\"fulltext\":\"\"}],\"status\":\"published\",\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"scientific-reports\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":false,\"externalIdentity\":\"scirep\",\"sideBox\":\"Learn more about [Scientific Reports](http://www.nature.com/srep/)\",\"snPcode\":\"\",\"submissionUrl\":\"\",\"title\":\"Scientific Reports\",\"twitterHandle\":\"\",\"acdcEnabled\":true,\"dfaEnabled\":true,\"editorialSystem\":\"stoa\",\"reportingPortfolio\":\"Scientific Reports\",\"inReviewEnabled\":true,\"inReviewRevisionsEnabled\":true}}],\"origin\":\"\",\"ownerIdentity\":\"4acd4e4c-f117-48df-87a4-84bcd0ff6bc1\",\"owner\":[],\"postedDate\":\"April 30th, 2025\",\"published\":true,\"recentEditorialEvents\":[],\"rejectedJournal\":[],\"revision\":\"\",\"amendment\":\"\",\"status\":\"under-review\",\"subjectAreas\":[{\"id\":47782336,\"name\":\"Health sciences/Cardiology\"},{\"id\":47782337,\"name\":\"Health sciences/Medical research\"},{\"id\":47782338,\"name\":\"Health sciences/Signs and symptoms\"}],\"tags\":[],\"updatedAt\":\"2025-07-29T18:08:16+00:00\",\"versionOfRecord\":[],\"versionCreatedAt\":\"2025-04-30 07:05:52\",\"video\":\"\",\"vorDoi\":\"\",\"vorDoiUrl\":\"\",\"workflowStages\":[]},\"version\":\"v1\",\"identity\":\"rs-6381125\",\"journalConfig\":\"researchsquare\"},\"__N_SSP\":true},\"page\":\"/article/[identity]/[[...version]]\",\"query\":{\"redirect\":\"/article/rs-6381125\",\"identity\":\"rs-6381125\",\"version\":[\"v1\"]},\"buildId\":\"XKTyCvWXoU3ODBz1xrDgd\",\"isFallback\":false,\"isExperimentalCompile\":false,\"dynamicIds\":[84888],\"gssp\":true,\"scriptLoader\":[]}","source_license":"CC-BY-4.0","license_restricted":false}